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EP1239472A1 - Anti-copy protection system for audio compact discs - Google Patents

Anti-copy protection system for audio compact discs Download PDF

Info

Publication number
EP1239472A1
EP1239472A1 EP01500143A EP01500143A EP1239472A1 EP 1239472 A1 EP1239472 A1 EP 1239472A1 EP 01500143 A EP01500143 A EP 01500143A EP 01500143 A EP01500143 A EP 01500143A EP 1239472 A1 EP1239472 A1 EP 1239472A1
Authority
EP
European Patent Office
Prior art keywords
audio
compact discs
data
protected
protection system
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP01500143A
Other languages
German (de)
French (fr)
Inventor
Hervé Auzanne
Alberto Torrejon Rosas
Carlos Garcia Abadillo
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
MPO Iberica SA
Original Assignee
MPO Iberica SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by MPO Iberica SA filed Critical MPO Iberica SA
Publication of EP1239472A1 publication Critical patent/EP1239472A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/0092—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which are linked to media defects or read/write errors
    • G11B20/00927—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which are linked to media defects or read/write errors wherein said defects or errors are generated on purpose, e.g. intended scratches
    • G11B20/00956—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which are linked to media defects or read/write errors wherein said defects or errors are generated on purpose, e.g. intended scratches said intentional errors occurring due to an invalid TOC
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00188—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised devices recording or reproducing contents to/from a record carrier
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00188—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised devices recording or reproducing contents to/from a record carrier
    • G11B20/00202—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which result in a restriction to authorised devices recording or reproducing contents to/from a record carrier wherein the copy protection scheme builds on multi-session recording, e.g. defective table of contents [TOC] in the 2nd session
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/00086—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy
    • G11B20/00572—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which change the format of the recording medium
    • G11B20/00615—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which change the format of the recording medium said format change concerning the logical format of the recording medium, e.g. the structure of sectors, blocks, or frames
    • G11B20/0063—Circuits for prevention of unauthorised reproduction or copying, e.g. piracy involving measures which change the format of the recording medium said format change concerning the logical format of the recording medium, e.g. the structure of sectors, blocks, or frames wherein the modification to the logical format mainly concerns management data, e.g., by changing the format of the TOC or the subcode
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G11B27/32—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier
    • G11B27/327—Table of contents
    • G11B27/329—Table of contents on a disc [VTOC]
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00—Record carriers by type
    • G11B2220/20—Disc-shaped record carriers
    • G11B2220/25—Disc-shaped record carriers characterised in that the disc is based on a specific recording technology
    • G11B2220/2537—Optical discs
    • G11B2220/2545—CDs

Definitions

  • the present invention refers to a system for protection against copying of audio compact discs, specifically conceived for avoiding their fraudulent copying with personal computers, when up until now said compact discs can be played and copied.
  • An audio compact disc from now on "audio CD” is divided basically into three sections: Lead-in or TOC, Program Area and Lead-out.
  • the Lead-in which is the first piece of information that a CD reader reads upon insertion of the CD, indicates the information of the CD contents (duration, number of tracks, location of the songs in the disc, ISRC codes, etc.)
  • the Program Area in which are the contents of the songs (the music.)
  • the Lead-out there is a Lead-out that does not contain anything and just indicates the end of the CD.
  • the CD has pits from the Lead-in to the Lead-out, which when read by a CD reader are converted into the digital data 0 or 1 (bit.)
  • This audio CD structuring allows, besides the disc being played back in any of the CD readers in the market, such as home CD readers, discman, car readers, mini-systems and stereo systems as well as in personal computers.
  • any audio CD can be copied with the aid of an audio CDR recorder and also with a personal computer, in such a way that these copies entail great losses to the recording industry.
  • audio CDR recorders are not very extended, and given that most music users own only a CD reader, the use of personal computers is very common, it is by the use of computers that the aforementioned copies are made and upon which an impediment is to be imposed.
  • the anti-copy protection system that the invention proposes allows the CD playing back with no problem in any reader of the aforementioned and its playing back or copying into an audio cassette, a audio CDR recorder, a DAT unit, etc., and impedes the playing back, and therefore the partial or complete copying of a CD in a personal computer.
  • said system consists in modifying the contents of the Lead-in or TOC, so that when putting the CD in a personal computer reader, the reader cannot read the data contents of the CD; however, said data can be read and recognized by an audio reader.
  • the idea is to modify the information or data of the Lead-in or TOC that tell the computer the distribution of information of each sector so that the computers believe that the data that contain the protected songs have a different distribution from the actual one. By doing it this way, when trying to read one or more protected songs with a personal computer, the reader will jump to those songs which are unprotected (if there are any) in such a way that the protected song will not be prone to be copied or played back.
  • the protection system is carried out track by track, so that CD's can be protected partially or wholly, in such a way that when a partial protection is made, those songs that are not protected can be read and copied.
  • the songs are distributed in the following fashion:
  • the Program Area or CD content is divided into minutes and each minute divided into seconds and each second into 75 sectors. Each sector is in turn divided into 3,224 bytes. The way the bytes are distributed depends on the way the CD was recorded, which corresponds to the disc contents and are basically three:
  • the CD's can be played back with no problems in audio readers, but if the CD's are being played back in a personal computer only those songs which are not protected, in case at least one of the songs has been left unprotected because it was considered that its copying or duplication does not entail any problems. In a more specific way, when trying to play a protected disc in a personal computer, only those recordings unprotected can be played back, with the computer skipping those that are protected.

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Security & Cryptography (AREA)
  • Signal Processing (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)
  • Storage Device Security (AREA)

Abstract

The system is especially conceived for avoiding the copying of audio compact discs in personal computers but allowing their perfect playing back in any of the audio readers in the market and allowing as well their being copied in CDR recorders (or similar.) For said purpose, the contents of the Lead-in or TOC are modified, specifically editing from audio mode to ROM mode so that the audio reader plays back correctly the protected CD and makes a computer believe that the data the protected songs contain have a distribution inside the disc sectors different than the actual one, so that when trying to read any one protected song, it cannot play it and when trying to copy the entire CD an error message displays.

Description

    OBJECT OF THE INVENTION
  • The present invention refers to a system for protection against copying of audio compact discs, specifically conceived for avoiding their fraudulent copying with personal computers, when up until now said compact discs can be played and copied.
    • BACKGROUND OF THE INVENTION
  • An audio compact disc, from now on "audio CD" is divided basically into three sections: Lead-in or TOC, Program Area and Lead-out. The Lead-in, which is the first piece of information that a CD reader reads upon insertion of the CD, indicates the information of the CD contents (duration, number of tracks, location of the songs in the disc, ISRC codes, etc.) After the Lead-in comes the Program Area, in which are the contents of the songs (the music.) Finally, there is a Lead-out that does not contain anything and just indicates the end of the CD. The CD has pits from the Lead-in to the Lead-out, which when read by a CD reader are converted into the digital data 0 or 1 (bit.) In CD readers there is a converter which converts said digital data into analog data: said analog data are the music.
  • This audio CD structuring allows, besides the disc being played back in any of the CD readers in the market, such as home CD readers, discman, car readers, mini-systems and stereo systems as well as in personal computers.
  • Obviously, any audio CD can be copied with the aid of an audio CDR recorder and also with a personal computer, in such a way that these copies entail great losses to the recording industry.
  • Although audio CDR recorders are not very extended, and given that most music users own only a CD reader, the use of personal computers is very common, it is by the use of computers that the aforementioned copies are made and upon which an impediment is to be imposed.
    • DESCRIPTION OF THE INVENTION
  • The anti-copy protection system that the invention proposes allows the CD playing back with no problem in any reader of the aforementioned and its playing back or copying into an audio cassette, a audio CDR recorder, a DAT unit, etc., and impedes the playing back, and therefore the partial or complete copying of a CD in a personal computer.
  • For said purpose, and in a more specific fashion, said system consists in modifying the contents of the Lead-in or TOC, so that when putting the CD in a personal computer reader, the reader cannot read the data contents of the CD; however, said data can be read and recognized by an audio reader.
  • Specifically, the idea is to modify the information or data of the Lead-in or TOC that tell the computer the distribution of information of each sector so that the computers believe that the data that contain the protected songs have a different distribution from the actual one. By doing it this way, when trying to read one or more protected songs with a personal computer, the reader will jump to those songs which are unprotected (if there are any) in such a way that the protected song will not be prone to be copied or played back.
  • The protection system is carried out track by track, so that CD's can be protected partially or wholly, in such a way that when a partial protection is made, those songs that are not protected can be read and copied.
    • PREFERRED EMBODIMENT OF THE INVENTION
  • In an audio CD, the songs are distributed in the following fashion:
  • The Program Area or CD content is divided into minutes and each minute divided into seconds and each second into 75 sectors. Each sector is in turn divided into 3,224 bytes. The way the bytes are distributed depends on the way the CD was recorded, which corresponds to the disc contents and are basically three:
    • Audio Mode (Audio CD): the 3,224 bytes per sector are divided in the following fashion: 2,352 bytes for audio data, 392 bytes for the first EDC/ECC, 392 bytes for the second EDC/ECC and 98 bytes for the byte control.
    • Mode 1 (CD ROM): the 3,224 bytes per sector are divided in the following fashion: 12 bytes for synchronism, 4 bytes for the Header, 2,048 bytes for the user data, 4 bytes for EDC, 276 for ECC and 882 bytes for the first and second EDC/ECC and byte control.
    • Mode 2 (CD ROM): the 3,224 bytes per sector are divided in the following fashion: 12 bytes for synchronism, 4 bytes for the Header, 2,048 bytes for the user data, 4 bytes for EDC, 276 for ECC and 882 bytes for the first and second EDC/ECC and byte control.
  • By modifying the data in the Lead-in or in the TOC, which control the CD byte distribution with software prepared for this effect, it so happens that when putting a protected CD into the computer, the computer believes the data distribution is in a mode (Mode 1 or Mode 2) which does not correspond to the Mode (Audio Mode) with which the CD was actually recorded. However, when putting said protected CD into an audio reader, the reader will recognize the Mode (Audio Mode) with which the audio CD content was recorded.
  • Once the Lead-in has been modified, both during pre-mastering and mastering, the CD's can be played back with no problems in audio readers, but if the CD's are being played back in a personal computer only those songs which are not protected, in case at least one of the songs has been left unprotected because it was considered that its copying or duplication does not entail any problems. In a more specific way, when trying to play a protected disc in a personal computer, only those recordings unprotected can be played back, with the computer skipping those that are protected.

Claims (3)

  1. Anti-copy protection system for audio compact discs which is especially conceived for impeding the recording of the contents of said compact discs in a computer, characterized in that it consists in modifying the contents of the disc Lead-in or TOC so that the Program Area cannot be played back by the computer reader but it can be played back in an audio reader
  2. Anti-copy protection system for audio compact discs according to claim 1, characterized in that the modification of the Lead-in or TOC consists in editing the information that indicates the computers the data distribution in each one of the compact disc sectors, so that to the computer readers the data that arrive regarding the distribution of the protected songs are different from the actual distribution, data which do not affect audio readers currently in the market, because they are ROM-featured.
  3. Anti-copy protection system for audio compact discs according to previous claims, characterized in that the data edited for the computer readers can affect the CD partially or wholly, in order to avoid its complete or partial copying, allowing the playing back and recording of some of its tracks.
EP01500143A 2001-02-23 2001-06-08 Anti-copy protection system for audio compact discs Withdrawn EP1239472A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ES200100436A ES2180412B1 (en) 2001-02-23 2001-02-23 ANTI-COPY PROTECTION SYSTEM FOR COMPACT AUDIO DISCS.
ES200100436 2001-02-23

Publications (1)

Publication Number Publication Date
EP1239472A1 true EP1239472A1 (en) 2002-09-11

Family

ID=8496873

Family Applications (1)

Application Number Title Priority Date Filing Date
EP01500143A Withdrawn EP1239472A1 (en) 2001-02-23 2001-06-08 Anti-copy protection system for audio compact discs

Country Status (2)

Country Link
EP (1) EP1239472A1 (en)
ES (1) ES2180412B1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2407911A (en) * 2003-11-07 2005-05-11 Macrovision Europ Ltd Copy protection of optical discs
GB2414338A (en) * 2004-05-19 2005-11-23 Macrovision Corp Copy Protection Of Optical Disks Against Devices Which Parse Control or Navigation Data

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5124963A (en) * 1987-03-11 1992-06-23 Sony Corporation Method and apparatus for selectively changing archival information on an optical disk
EP0930615A2 (en) * 1998-01-20 1999-07-21 Fujitsu Limited Data storage device and control method therfor

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB9912312D0 (en) * 1999-05-26 1999-07-28 Dilla Limited C The copy protection of digital audio compact discs

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5124963A (en) * 1987-03-11 1992-06-23 Sony Corporation Method and apparatus for selectively changing archival information on an optical disk
EP0930615A2 (en) * 1998-01-20 1999-07-21 Fujitsu Limited Data storage device and control method therfor

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
POHLMANN: "THE COMPACT DISC HANDBOOK", COMPACT DISC HANDBOOK, OXFORD, OUP, GB, 1992, pages 213 - 221, XP002033060 *

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2407911A (en) * 2003-11-07 2005-05-11 Macrovision Europ Ltd Copy protection of optical discs
GB2414338A (en) * 2004-05-19 2005-11-23 Macrovision Corp Copy Protection Of Optical Disks Against Devices Which Parse Control or Navigation Data
GB2414338B (en) * 2004-05-19 2008-10-29 Macrovision Corp Improvements in or relating to the copy protection of optical discs
US7706661B2 (en) 2004-05-19 2010-04-27 Macrovision Corporation Copy protection of optical discs using redundant control data

Also Published As

Publication number Publication date
ES2180412B1 (en) 2004-06-01
ES2180412A1 (en) 2003-02-01

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